JP2004526385A - Method and apparatus for storing data in or reading data from a storage medium, and storage medium - Google Patents

Abstract

The present invention relates to a method and an apparatus for storing data (5, 6) in a storage medium (17) and reading data from the storage medium (17). In order to enable compatibility between different file systems (JAFS, UDF), the data structure is composed of a first management area (10) belonging to a first file system (JAFS) and a second file system (UDF). ) Is stored in the second management area (12). Thus, a so-called bridge disk that can be read in different file systems is realized.

Description

【Technical field】
[0001]
The present invention relates to a method of storing data in a storage medium, wherein the data is stored in at least a part of a data area, and a data structure representing a structure of the data is stored in a first management area.
[0002]
Furthermore, the present invention relates to an apparatus for storing data in a storage medium, storing data in at least a part of a data area and storing a data structure representing the structure of the data in a first management area of a first file system. .
[0003]
Further, the present invention has a reading means for reading data stored in at least a part of the data area, and reading a data structure representing the structure of the data stored in the first management area of the first file system. The present invention relates to an apparatus for reading data stored in a recording medium.
[0004]
Further, the present invention relates to a storage medium having a data area for storing data at least partially, and a first management area of a first file system for storing a data structure representing the structure of the data.
[Background Art]
[0005]
In the field of digital video recording (DVR), a particular file system, the so-called JAFS (Joint Approach File System), has been selected for recording digital video files on DVR discs. Such a JAFS DVR disc has a lead-in area and a lead-out area, between which a video file is written to the data area. Further, such a DVR disc has a management information area (MIA) for management purposes. MIA stores the structure of the files contained on the DVR disc.
DISCLOSURE OF THE INVENTION
[Problems to be solved by the invention]
[0006]
However, in principle such DVR discs are suitable for use in other electronic devices such as personal computers (PCs), but in the field of PCs a different file system, the so-called universal disc format Since a (UDF) file system is used, a DVR disc containing a video file according to JAFS cannot be read by a PC. These two different file systems make DVR discs containing video files in JAFS format intended for use in digital video recorders unusable in PCs. Conversely, DVR discs containing typical computer data according to the UDF file system cannot be read on a digital video recorder.
[Means for Solving the Problems]
[0007]
It is therefore an object of the present invention to enable compatibility between different file systems.
[0008]
For this purpose, the data structure is further stored in a second management area of a second file system, and a head of the second management area is written outside the first management area and outside the data area. This is achieved by providing a method of storing data of the type described above.
[0009]
The object is further to write the data structure in a second management area of a second file system, wherein the head of the second management area is written outside the first management area and outside the data area. This is achieved by providing an apparatus for storing data of the type described above, characterized by writing means.
[0010]
The object is further configured such that the reading unit reads a data structure representing the structure of the data and stored in a second management area of a second file system, wherein the head of the second management area is This is achieved by providing an apparatus for reading data of the type described above, which is arranged outside the first management area and outside the data area.
[0011]
The object further includes a second management area of a second file system for storing the data structure, wherein a head of the second management area is located outside the first management area and in the data area. This is achieved by providing a recording medium of the type described above, characterized in that it is arranged externally.
[0012]
This object makes it possible to mirror the structure of a first file system such as JAFS to the equivalent of a second file system such as a UDF file system. As a result, the JAFS and UDF file systems have the same view in the stored data. This enables compatibility between different file systems. In particular, the present invention enables read compatibility with standard UDF implementations while maintaining read and write compatibility for consumer recorders, especially digital video recorders.
[0013]
Thus, a bridge application or bridge configuration that links different file systems and makes the different file systems compatible is achieved. The bridge application or bridge configuration creates a bridge disk that is readable by any PC with, among other things, a UDF reader and readable and writable by any consumer DVR recorder.
[0014]
The term "data structure" includes all types of structures related to data stored on a storage medium. In particular, “data configuration” refers to a volume configuration representing the configuration of logical and / or physical volumes, a file configuration representing the configuration of a file containing data, and / or an allocated and / or allocated for storing data on the medium. Contains a space bitmap that represents unfilled spaces. The information stored in the management area facilitates the handling and management of the data stored in the medium.
[0015]
Preferably, a first section of the first management area and a first section of the second management area are respectively written at different predetermined positions on the medium, and each space required for the management area is different. If the predetermined size is exceeded, one or more additional sections are written anywhere on the medium, thereby marking the additional sections in each other management area as occupied space. Thus, since each management area is divided into several parts, no limit is imposed on the amount of information stored in the management area. Thus, flexibility and compatibility are further increased.
[0016]
Preferably, a modification of data and / or files performed by a first file system such as JAFS is determined, and the management area of the second file system is updated. Thus, if a medium is re-inserted into a system that mainly uses the second file system, the compatibility of the medium with both of these file systems is still guaranteed.
[0017]
Alternatively, instead of just updating the management area of the second file system, the second management area is completely rebuilt, thereby removing the previously saved second management area. Both of these alternatives can maintain compatibility even when data and / or files change.
[0018]
These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter with reference to the accompanying drawings.
BEST MODE FOR CARRYING OUT THE INVENTION
[0019]
FIG. 1 shows a diagram of a JAFS-only disc 1 comprising a lead-in area 2 and a lead-out area 3. The data area 4 is arranged between the lead-in area 2 and the lead-out area 3. The data area 4 contains blocks 5 and 6 of data, and includes unused or unallocated disk space 7, 8 and 9 between blocks 5 and 6 and before and after these blocks.
[0020]
Typically, the data stored in blocks 5 and 6 is a video file. Therefore, such a JAFS-only disc 1 is generally used in a digital video recorder using JAFS.
[0021]
The first management area, that is, the MIA 10 is arranged between the lead-in area 2 and the data area 4 at a certain position in the JAFS dedicated disk, particularly at a certain physical sector. However, there is a further area of unused or unallocated disk space 11 between the lead-in area 2 and the MIA 10 and another file system between the data area 4 and the lead-out area 3. There is an additional area 11a of unused, unallocated or unallocated disk space that is reserved for use by.
[0022]
It should be noted that the MIA 10 extends to the data area 4, so that the MIA 10 may be divided into a plurality of MIA parts. This places some parts in the areas of disk space 7, 8 and 9 that were not previously used. Thus, the JAFS area 4a is defined as a combination of the MIA 10 and the data area 4.
[0023]
When such a JAFS disc 1 is inserted into a personal computer (PC), the PC generally cannot read the disc because the PC uses a different file system, that is, a file system conforming to the UDF standard. . Therefore, a JAFS / UDF bridge application that writes both UDF and JAFS file system structures on a DVR disc is proposed. This enables read compatibility with standard UDF implementations while maintaining read and write compatibility with consumer recorders. Thereby, both file systems, namely the JAFS and UDF file systems, have the same view on the stored data.
[0024]
Reference is now made to FIGS. FIG. 2 shows the steps performed by the bridge application when a JAFS-only disc such as that of FIG. 1 is first inserted into a PC. In the first step S1, a UDF partition is defined so as to start before the JAFS area 4a or in the JAFS area 4a. Thus, for different file systems JAFS and UDF, each management area, at least the top of the management area, ie, the top of the first management area such as MIA, and the top of the second management area such as UDF structure Can be separated by writing to different partitions.
[0025]
Then, in step S2, a second management area, the UDF volume structure area 12 (FIG. 3), is stored on the disk, starting at area 13 outside of the JAFS area, and at positions 14 and Follow at 15. In a further step S3, the UDF structure is initialized according to the management in the MIA. In particular, the unallocated space bitmap is initialized taking into account the JAFS file system structure and disk space.
[0026]
Further, step S4 mirrors the JAFS structure to the UDF equivalent. Here, these structures are packed together to limit the number of disk areas to be used. As a result, file and directory entries for the management area of the UDF file system are generated by pointing to the same data as the MIA in JAFS.
[0027]
By step S5, the space occupied by the UDF file system structure area 12 is marked, preferably using the disc recording chain (recoding chain), in the hidden system file JAFS and / or clearly marked as "UDF structure". Thus, a new management area, that is, MIA'16 is generated.
[0028]
The result is the JAFS-UDF bridge disk 17 according to FIG. This JAFS-UDF bridge disk 17 contains the same video files arranged in data blocks 5 and 6 as those dedicated to JAFS according to FIG. Furthermore, the lead-in area 2 and the lead-out area 3 remain unchanged during the conversion of the JAFS-dedicated disc 1 to the JAFS-UDF bridge disc 17. However, compared to the JAFS dedicated disk 1, the JAFS-UDF bridge disk additionally has the UDF partition and UDF structure area 12.
[0029]
If write access is allowed to the UDF portion of the disc, for example to allow erasure of files, the bridge application will keep the JAFS view consistent or will make the disc last consistent. Can be That is, making the disc suitable for use in a DVR recorder.
[0030]
Since the DVR recorder does not need to have knowledge of UDF, the JAFS structure can be updated by the DVR recorder without updating the UDF structure. For example, in a DVR recorder, a file may be removed and a new file may be added. When such changes occur, and when such discs are reinserted into the PC, the bridge application needs to check what changes have been applied.
[0031]
FIG. 4 shows the steps to be performed by the bridge application after such reinsertion of the bridge disk 17 and after the data change has been performed.
[0032]
In step 6, the bridge application compares the JAFS view with the UDF view to determine changes applied to JAFS since the UDF file system was updated. Then, in step S7, the UDF structure is updated according to the determined change. Alternatively, the UDF structure can be reconstructed in step S7, which removes the previously generated structure used for the UDF view.
[0033]
Preferably, the first management area, eg MIA, is used to mark the space occupied by the second management area, in particular by using a disk recording chain, so that the second management area, ie the UDF structure Updated after the region is constructed. Thus, the sector of the disk allocated to the management area of the second file system is prevented from being accessed by the first file system.
[0034]
Further, preferably, both the management area of the first file system and the management area of the second file system are updated or reconstructed after data and / or files executed by the second file system. Is done. This may be performed in real time. This is convenient to allow editing of DVR recordings and files stored in the UDF file system.
[0035]
It should be noted that some restrictions on JAFS need to be defined to enable UDF compatibility. The first constraint is that the starting offset in the disk area record is limited to zero. Another limitation is that, except for the possibly last disk area record in the chain, the end offset in the disk area record is set to sector size-1.
[0036]
Additional constraints on UDF may be introduced to allow compatibility for JAFS. That is, defect management of the drive (spare area = 0) is not allowed.
[0037]
For symmetry reasons, further embodiments are allowed where the standard UDF implementation also writes a bridge disc. In this case, a hidden system file “JAFS structure” that is not moved (removed) is provided. The bridge application determines the updates that have been applied to the UDF file system since the JAFS file system was updated, and by applying only those changes to the JAFS file system, the JAFS after the UDF structure was changed. -Restore UDF consistency.
[0038]
The above-mentioned bridge application is not limited to the JAFS-UDF bridge, but is similarly applied to JADF and other file systems, or even to UDF and other file systems even if they have different versions of UDF. It should be noted that this can be done.
[0039]
FIG. 5 is a schematic diagram of the device 18 for storing data in the bridge disk. The device 18 has a reading and writing means 19 for reading data from a disk 20 which is driven in particular by a driving means 21. The reading means 19 is capable of reading data stored on a JAFS-dedicated disk, similarly to the JAFS-UDF bridge disk.
[0040]
The JAFS management area, ie, the MIA, is read by the reading means 19 and transmitted to the conversion means 24 which is controlled by the microprocessor 23 and converts the data structure of the JAFS into the data structure of the UDF file system via the data bus 22. These converted data structures are sent to the second management area, that is, the writing means 19 for writing the converted data structures to the UDF structure of the UDF file system, to generate the bridge disk according to FIG. Sent through.
[0041]
The present invention allows a PC to create and modify audio / video material on DVR discs according to both UDF and JAFS standards. The resulting bridge disk is at least readable by any PC with a UDF recorder and readable and writable by any consumer recorder.
[Brief description of the drawings]
[0042]
FIG. 1 shows a diagram of a JAFS dedicated disc.
FIG. 2 shows a flowchart of a method to be performed by a bridge application when a JAFS-only disc is first inserted into a PC.
FIG. 3 shows a diagram of a JAFS-UDF bridge disc.
FIG. 4 shows a flowchart of a method performed by a bridge application after reinserting a bridge disk into a PC.
FIG. 5 is a schematic view of an apparatus for storing data on a JAFS-UDF bridge disk.

Claims (14)

A method of storing data on a storage medium, comprising:
The data is stored in at least a part of a data area,
In the method, a data structure representing a structure of the data is stored in a first management area of a first file system.
The data structure is stored in a second management area of a second file system, and a head of the second management area is written outside the first management area and outside the data area. Method. The first section of the first management area and the first section of the second management area are respectively written at different predetermined locations on the medium, and each space required for the management area is determined by a predetermined amount. If the size is exceeded, one or more further sections are written at any location on the medium, marking the further sections in each other management area as occupied space. Item 2. The method according to Item 1. A volume structure representing the structure of logical and / or physical volumes, a file structure representing the structure of a file containing the data, and / or a space bitmap representing space allocated and / or unallocated for storing data. Is stored in said first management area and / or in said second management area. The method of claim 1, wherein a partition is defined such that the second file system starts at an address or beginning outside the area of the first file system. The method of claim 1, wherein the first management area and the second management area include file and directory entries pointing to the same data. The first management area is updated after the second management area is constructed, in order to mark the space occupied by the second management area, especially by utilizing a disk recording chain. The method of claim 1, characterized in that: After the change of the data and / or file is performed by the first file system, the change is determined, and the second management area of the second file system is updated according to the change. The method according to claim 1, characterized in that: After the data and / or file changes have been performed by the first file system, the changes are determined and the second management area of the second file system is rebuilt, thereby preserving it 2. The method according to claim 1, wherein the second managed area is removed. 2. The management area of the first and second file systems is updated or rebuilt after the change of the data and / or file is executed by the second file system. The method described in. An apparatus for storing data in a storage medium, storing data in at least a part of a data area and storing a data structure representing the structure of the data in a first management area of a first file system.
A writing means for writing the data structure in a second management area of a second file system, wherein at this time the head of the second management area is written outside the first management area and outside the data area. Equipment to do. Converting means for converting the data structure of the first file system into a data structure of the second file system enabling the same view of the stored data as the first file system;
Writing means configured to write the converted data structure outside the first management area and outside the data area to the second management area of the second file system. An apparatus according to claim 10, characterized in that it is characterized by: Data stored in at least a part of the data area, and read means for reading a data structure stored in the first management area of the first file system, the data structure representing the structure of the data; Device that reads the data
The reading means is configured to read a data structure representing a structure of the data and stored in a second management area of a second file system. An apparatus, wherein the apparatus is arranged outside a management area and outside the data area. A data area for storing data at least partially;
A storage medium having a first management area of a first file system for storing a data structure representing the structure of the data,
A second management area of a second file system for storing the data structure;
The storage medium according to claim 1, wherein a head of said second management area is located outside said first management area and outside said data area. The first section of the first management area and the first section of the second management area are respectively located at different predetermined positions on the medium, and the respective space required for the management area is predetermined. If the size is exceeded, one or more further sections may be located at any location on the medium, each other management area including information indicating the further section as occupied space. 14. The storage medium according to claim 13.

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